I am getting ready to pull the head off my 4.0 this weekend to replace the valve guides. Do i need to remove the intake and exhaust manifolds first or can they all come out as once piece?

Thanks,

Jon

deathtrap

09-12-2013 09:28 PM

One piece is the way to go. Talk a buddy or two into helping you lift it off. It weights a $*** load. Or use a cherry picker if ya got one.

Que89YJ

09-13-2013 05:37 AM

Remove the drivers fender to get at the bolts for the intake and exhaust manifolds. It makes getting the bolts on and off so so so much easier. It takes you 1/2 hr to remove the fender and it will save blood donation and quarters into the swear jar. Yes they need to come off. The head is heavy but you can move it by yourself. You might want to take the time to do some maintenance while you are doing it. Clean the pistons, clean the throttlebody, intake, and clean the IAC. Check the exhaust manifold for any cracks!

Rino1425

09-13-2013 01:14 PM

I am going to replace the exhaust mani when i put the head back in. Ive taken the fender off before, but i think it might just be better to remove the whole thing. The ABS is a pain to get around. Im going to re-ring it while im in there since the heads off. I hope the bore is still square.

Que89YJ

09-13-2013 01:18 PM

ReRinging the engine?

Rino1425

09-13-2013 01:24 PM

yeah, drop the oil pan so i can get the pistions out from the top. I think the rings are starting to wear.

95yj0645

09-13-2013 02:04 PM

You might as well just pull the whole thing out if you are going to get that deep. I had mine out in about an hour and a half. Remove the grill with radiator, it take all of 5 minutes. If I was going to just pull the head off I would take the intake and exhaust off in the jeep and set it off to the side. The manifold bolts aren't hard to get to if you have a few wobble extensions, and ratchet wrenches. More than likely your int/exh gasket needs replaced anyways. Just my two cents to save some cusswords ,and wrenching your back more than wrenching on the Jeep.

Que89YJ

09-13-2013 06:28 PM

How many miles on the engine? Did you run a leak down test & compression test? I didn't know your issues were that bad.

deathtrap

09-13-2013 10:14 PM

Quote:

Originally Posted by Que89YJ
(Post 15964441)

Remove the drivers fender to get at the bolts for the intake and exhaust manifolds. It makes getting the bolts on and off so so so much easier. It takes you 1/2 hr to remove the fender and it will save blood donation and quarters into the swear jar. Yes they need to come off. The head is heavy but you can move it by yourself. You might want to take the time to do some maintenance while you are doing it. Clean the pistons, clean the throttlebody, intake, and clean the IAC. Check the exhaust manifold for any cracks!

It takes maybe 3 min to remove the manifolds from the head once the head is on the bench, and you have all the room in the world.:confused: But hay, what ever works for you.

Que89YJ

09-14-2013 04:55 AM

Ok. Suggestion made. Most people have a difficult time with the middle bolts on the manifold. You are leaving it on and disconnecting the down pipe?

Rino1425

09-14-2013 07:54 AM

The mileage is around 100k. I ran a compression test and a few cylinders are around 40psi. I havent done a leak down test yet as no place around here rents the tester. I have already had the down pipe disconnected a week ago, so i know the bolts are easy to get off now. I am burning oil on decel when under high vaccum and at start up. When under throttle, there is no smoke really.

deathtrap

09-14-2013 08:19 AM

Quote:

Originally Posted by Que89YJ
(Post 15993273)

Ok. Suggestion made. Most people have a difficult time with the middle bolts on the manifold. You are leaving it on and disconnecting the down pipe?

Yes, disconnect the down pipe, vac, hoses,throttle ,ect. lift the head and manifolds off as one unit. It goes back on the same way. Easy and painless.:thumbsup:

Rino1425

09-14-2013 09:42 AM

Quote:

Originally Posted by deathtrap
(Post 15995977)

Yes, disconnect the down pipe, vac, hoses,throttle ,ect. lift the head and manifolds off as one unit. It goes back on the same way. Easy and painless.:thumbsup:

Perfect. Sound like the valve guides to you that are bad?

deathtrap

09-14-2013 05:06 PM

Quote:

Originally Posted by Rino1425
(Post 15997545)

Perfect. Sound like the valve guides to you that are bad?

You really need to find out why the compression is low. (where it is leaking)There is a leak-down tester somewhere near you. FIND IT!. You may get away with just a valve job.

Que89YJ

09-14-2013 09:49 PM

100k it's not enough to do rings. I would get the leak down tool before I pulled it apart. The engine should be good for 300k @100k no rings needed in theory. Valves are probably bad.